This invention relates to surgical instruments and, more particularly, to a novel electro-surgical dissection and cauterization instrument for use primarily in laparoscopic/endoscopic procedures.
Many surgical procedures of today involving the removal and/or cauterization of tissue (e.g. endometriosis, lysis of adhesions, cholecystectomy, appendectomy, etc.) are performed with an electro-surgical dissection and cauterization instrument either in open surgery where the surgeon has direct view and access to the operation site, or in combination with an endoscope. Referring to the endoscopic surgery and, in particular, laparoscopic surgery which refers specifically to the abdominal area, the surgeon first makes usually several small, spaced incisions through the abdominal wall of the anesthetized patient. A source of compressed CO.sub.2 is then delivered through one of the incisions to inflate the abdomen which effectively raises the abdominal wall above the organs and intestines of the patient. A space is thereby created therebetween which facilitates manipulation of surgical instruments which have been inserted into the abdomen through one of the incisions.
The surgeon views the internal operation site with a laparoscope which is a specialized type of scope inserted into the abdomen through an incision. The laparoscope is attached to a miniaturized, surgical camera assembly which operates by transmitting the image the camera is directed at inside the abdomen of the patient to the laparoscope eyepiece and/or a CRT screen in the operating room. A trochar is typically positioned within the incision to provide a smooth passageway for the instruments into and out of the abdomen. The electro-surgical instrument passes through the trochar to reach and perform surgery on the patient by the surgeon carefully manipulating the exposed end of the instrument.
Electro-surgical instruments are used primarily to separate and remove diseased tissue from healthy tissue such as polyps from the colon, for example. They are also used as probes to move tissue about during exploratory surgery. Supplying the instrument with controlled, electrical energy is well known in the art. With the patient properly grounded, a high frequency electric current is discharged at the distal, electrode end of the tool which augments its cutting capability while simultaneously cauterizing bleeding tissue and blood vessels. The electro-surgical instrument includes a proximal end with a plug permitting connection of the tool to an electro-surgical unit which supplies electric energy to the distal, electrode end of the tool. A rigid, linear insulating sleeve surrounds the instrument which delivers electric energy from the proximal, plug end to the distal, electrode end which itself is formed of electrically conductive material such as stainless steel.
The instrument's distal electrode may be found in a variety of configurations, each different configuration serving a different, specific function. For example, a working tip electrode in the shape of a snare or hook is used for grasping and pulling at tissue while a working tip electrode in the shape of a flattened spatula is used primarily to move tissue about and/or to cauterize bleeding tissue. Many other working tip electrode configurations appear on the market every day as the needs and likes of surgeons change.
In most, if not all, of the dissecting tools available today, the working tip electrode of the instrument just described extends directly from the distal end of the insulating sleeve. As such, there is a minimum of distance between the sleeve and the working tip electrode which, in many instances of use, obstructs or impairs the surgeon's view of the operation site as viewed in either complete open surgery or with a laparoscope during the procedure just described. The problem exists due to the small size of the working tip electrode in relation to the relatively large diameter of the sleeve from which it extends.
A second problem surgeons have reported when using present day electro-surgical instruments is that the portion of the working tip electrode directly adjacent the sleeve occasionally makes inadvertent contact with healthy tissue surrounding the surgical work site. This has resulted in unintentional cauterization of healthy tissue which poses serious consequences to both patient and surgeon alike.
It is therefore a principle object of the present invention to provide an electro-surgical instrument including a rigid arm extending between the distal, working tip electrode and the insulating sleeve. The arm includes at least a portion thereof laterally offset from the longitudinal axis of the sleeve whereby obstruction of the surgeon's view of the working tip electrode and surgical work site by the sleeve is substantially reduced.
It is a further object of the present invention to provide an electro-surgical instrument which provides an electrical insulating layer along the entire length of the tool up to the exposed working tip electrode such that inadvertent cauterization of tissue with portions of the tool other than the working tip electrode is eliminated.
It is another object of the present invention to provide a single-use, disposable, electro-surgical and cauterizing instrument for endoscopic procedures which is designed for easy handling and use by the surgeon.
Other objects will in part be obvious and in part appear hereinafter.